Control for a radio set



July 7, 1936.

E. C. BOOTH CONTROL FOR A RADIO SET Filed Jan. 20, 1934 5 Sheets-Sheet l July 7, 1936. E. c. BOOTH 2,046,605

'CONTROL FOR A RADIO SET Filed Jan. 20, 1934 5 Sheets-Sheet 2 r I \I. 159 4. 59 j a 53 66 70 52 L :i! 62 a 7 76 Q 6 I f: N f g I R l I 67 62 5 f i I I I I I 4i- .Zf 4 I II I i h y I I 7 :l 15 1 l Z9 jg X X0 X42517 A I i j- E. c. BOOTH 2,046,605

CONTROL FOR A RADIO SET Filed Jan. 20, 1934 5 Sheets-Sheet 3 Jul 7, 1936. E c gOOTH 2,046,605

CONTROL FOR A RADIO SET Filed Jan. 20, 1934 5 Sheets-Sheet 4 July 7, 1936.

CONTROL FOR A RADIO SET Filed Jan. 20, 1934 5 Sheets-Sheet 5 E. c. BO(IDT.H 2,046,605

Patented July 7, 1 936 UNITE STATES CONTROL FOR A RADIO SET corporation of Indiana Application January 20, 1934, Serial No. 707,569

6 Claims.

My invention relates to control units for automobile radio sets in which it is customary to locate the control unit apart from the radio set itself. Such control units usually embody a rotatable element mechanically connected to the tuning condenser of the radio set, and one or more pieces of adjustable electrical apparatus, such as a rheostat, electrically connected to the radio set. In some cases, the pieces of adjustable apparatus are all located in close association with the radio set and mechanically connected to operating members in the control unit.

It is the object of my invention to produce a control unit for use in conjunction with an automobile radio set, which unit will be compact, at

tractive in appearance, and economical to manufacture. A further object of my invention is to produce a control unit which may be mounted in a variety of positions and in which the index that indicates the condition of tuning adjustment may be disposed in any desired position relative to the remainder of the control unit. A still further object of my invention is to produce a control unit in which there will be no necessity for gearing or other speed-reducing device in the tuning mechanism.

In carrying out my invention I form the base of the control unit as a hollow arm adapted to be. attached to the steering-post of an automobile and to be secured in any desired position of angular adjustment about the axis of such steeringpost. On the outer end of this arm, I mount a rotatable hollow knob of relatively large diameter which is adapted to be mechanically connected to the tuning condensers of the radio set so that the set maybe tuned by rotation of the knob. Within the knob, and stationarily supported from the arm constituting the base of the unit, I may provide a rheostat or other adjustable apparatus adapted for the electrical control of the radio set; or, if desired, I may mount all the adjustable electrical devices in the set and mechanically connect them with control members carried from the hollow arm.

The arm also carries a support bearing an index cooperating with an annular series of graduations on the control knob, and this support is r0- tatable about the axis of the control knob so that such index can be disposed at any desired angular position. The control knob itself is angularly adjustable about its own axis relative to the mechanism connecting it to the tuning condensers, so that the position of the annular series of graduations it carries can be properly coordinated with the tuning condensers.

The accompanying drawings illustrate my invention: Fig. 1 is a plan view of the complete control unit; Fig. 2 is a plan of the base of the unit with a part of such base broken away on the line 2--2 of Fig. 3; Fig. 3 is a side elevation 5 of the complete control unit; Fig. 4 is a fragmental vertical section on the line 44 of Fig. 1; Fig. 5 is a fragmental plan of the outer end of the base with the control knob removed, some parts being broken away for clearness of illustra- 10 tion; and Fig. 6 is a top plan view of the rheostatsupport located within the control knob; Fig. 7 is a'view similar to Fig. 4, but illustrating a modified construction; Fig. 8 is an elevation indicating the manner in which the control mechanism 15 of Fig. 7 is operatively connected with the adjustable devices of the radio set; and Fig. 9 is a plan view of the control mechanism of Fig. '7.

The base of the control unit is formed as a hollow arm l9 which is conveniently a die-casting. 20 The inner end of the arm I 0 is shaped to conform to the curvature of an automobile steering-post l I and has associated with it a clamp l2 adapted to be tightened as by means of a clamp screw I3. On the outer end of the arm [0 there is formed a 5 circular enlargement l5 having in its upper face a circular depression or recess 15 separated from the remainder of the space within the arm ID by a bottom partition I! and a side wall l8.

In the partition I! there is a centrally located 30 opening 20 of a diameter to receive a bushing 2| which serves as a pivotal support for a Bowdenwire pulley 22. The pulley 22 is held in place in a circular depression 23 in the upper face of the partition I! by being provided with an out- 35 wardly projecting annular flange received beneath a washer 25 secured to the partition I! as by means of an annular series of screws 26. These parts are perhaps best shown in Fig. 4.

In the plane of the washer 25, the pulley 22 4.0 is provided with an annular groove 28 adapted to receive one end of a Bowden-wire 29 which extends to the radio set proper and has its end secured to a pulley on the shaft carrying the movable plates to the tuning condensers, as 45 hereinafter described in greater detail. As it leaves the groove 28 in the pulley 22, the wire 29 passes through a groove formed in the lower surface of the washer 25 and disposed tangentially to the pulley 22. Outwardly beyond the 50 groove 25, the wire 29 passes through an opening in the wall [8, such opening being enlarged at its rear end to receive the end of the Bowdenwire casing 30, the latter being secured to the arm ID as by means of a set-screw 3| (Fig. 5). 55

It is obvious that in a Bowden-wire control of this kind it is advisable to prevent rotation of the pulley 22 in a wire-unwinding direction beyond the point where the wire-end fastened to the pulley comes into alinement with the groove through which the wire leaves the pulley. I

bridges the area covered by the groove and which, for reasons that will become apparent hereinafter, lies at the same distance from the axis of the washer 25 as do the screws 26.

For the purpose of rotating the pulley 22, I

7 provide a hollow control knob 35, conveniently of somemolded insulating material. At its lower end,'the knob 35 has an inwardly directed flange 35th'e bottom surface of which is provided with an annular groove 37 to aiford clearance for the heads of the screws 26 and for the boss 33. The inner edge of the flange 36 rests upon a shoulder 38 formed on'the pulley 22 and located above the upper surface of the washer 25, as is clear from Fig. 4. The knob 35 is secured to the pulley 22 as by means of vertical screws 136 which pass through a washer 4! bearing on the upper face of the flange 36"and received in screw-threaded openings in the pulley 22. Conveniently, the upper surface of the shoulder 38 is roughened somewhat where it engages the lower surface of the flange 36, in order to prevent relative an nular movement of the pulley 22 and knob 35 when the screws 46 are tightened.

It will be apparent from the construction so far described that when the knob 35 'is secured to the pulley 22 by means of the washer 4| and screws 46 the knob may be turned torotate the pulley 22', thus causing longitudinal movement of the Bowden-wire 29 in its casing 30. This movement of the Bowden-wire is transferredinany convenient manner to the adjustable tuning condensers of the radio set. a

In the case of the device illustrated in Figs. 1 to 6, I contemplate that a rheostat or other electrical apparatus will be mounted within the knob 35. As a support for any such apparatus I employ a cup 45, conveniently in the form of a sheet-metal stamping, which has in its base an opening to receive the upper end of the bushing 2|. The cup may be secured to the bushing, as by soldering. The upper open end of the cup 55 is closed by a cover plate 46 secured to the cup by means of screws 5'! which pass through holes vin the cover 45 into ears 48 formed by inwardly bent portions of the upper edge of the cup 55.

Electrical apparatus mounted within the cup 55 ls'shown in the'drawings as comprising a combined-switch and rheostat 50 which is adapted to turn the radio set on or off and to control sound volume. The unit 56 is formed with an upwardly projecting central boss 5! which is screw-threaded exteriorly andwhich passes through a central opening in the cover 46 to receive a nut 52 .by means of which the unit 56 is clamped to the cover. The operating member of the unit 55 is inthe form of a shaft 53 which projects upwardly through the boss 51 and has its upper end slotted,

for the reception of the lower end of a key 54..

Upon the cover 46 there is mounted a plate 56 which isconveniently held in place by the same screws 41 that retain the cover in place on the cup. The plate 56 has a central opening and is conveniently formed of sheet-metal so that the edges of such openings can be deformed upwardly to form in the lower surface of the plate 56 a polygonal recess adapted to receive the polygonal head of a fitting 51 which extends upwardly through and beyond the plate 56. The fitting 51 has an axial recess suficiently large in diameter to receive the boss 5! and shaft 53 and is counterbored for the reception of the nut 52. At its upper end, the fitting 57 has an inwardly directed annular flange 58 slotted as at 59 to permit the passage of the tang of the key 54.

Upon the plate 55 there is supported an es-' cutcheon plate 6| which constitutes, in effect, a

closure ofthe open upper end of the knob 35.

The escutcheon plate 6! may have secured to its lower surface a collar 62, conveniently of sheetmetal and formed to receive. support from the body portion of the plate 56 beyond the central deformation therein. The escutcheon plate is held in place by a nut 53 which co-operates with screw-threads on the outer surface ofthe fitting 51 and' is located angularlyabout its axis by means of an ear 62 struck from the collar 62 and receivable in a hole 46 in the cover 66.

At its extreme upper end, the knob 35 is provided interiorly with an annular rabbet groove which receives the outer edge of the escutcheon plate The bottom of the rabbet groove just mentioned serves as a support for a ring 55: of celluloid or some other transparent material that bears. a series of graduations by which the condition of adjustment of the radio set is indicated, such graduations, as the knob 35 is rotated, being successively exposed through an opening 65 in the escutcheon plate 5 i.

An index for co-operation with the graduations Th opening 55 in the escutcheon plate 5! and a the opening .69 in the cover 45 are. disposed in alinement with each other, and directly below them I provide a small lamp bulb 12 light from which illuminates the index plate 58 and that portion of the dial 55 which is exposed through the opening 66.

The dial 55, which is indicated in chain-lines in Fig. 6, may be provided in its periphery with a notch '55 adapted to receive a boss 2'5 projecting upwardly from the bottom of the rabbet-groove in the upper end of the control knob 35. This arrangement insures that the dial 55 will always have the same angular position relative to the control member and, therefore, that the graduations on the dial 65 will accurately indicate the position of angular adjustment of the control member. a

The lamp 712 and the terminals of the control unitp50 are connected to wires '58 constituting a cable which leads downwardly through the bushing 2i, inwardly through the interior of the arm 55, and thence outwardly to the radio set through an opening 86 formed in the bottom wall of the inwardly through the interior of the arm l and emerges therefrom through an opening 8|, :from "which it'extends to the radio set.

If anadditional electrical control, such as a tone control,'for the radio set is desired, the bottom wall of the arm I 9 may be provided near its zouter end with an opening for the reception of such a control. As indicated in Figs. 3 and 4, 'a tone-Icontrol unit .82 may be mounted upon a -plate 83 isecure'dtoithe lowersurface of the arm l0. .The-tone c'ontrol unit 82 will be provided with an operating knob 85 secured to the'lower end of .a control shaft 85, which extends downwardly through the plate '83.

.In automobile-radio sets with remote control, the Bowden-wire Z9 is frequently used to rotate the tuning condensers in only one direction, such condensers being rotated in the opposite direction by means of a torsion spring. To prevent the-control pulley 2-2 and :knob 35 from rotating as the result of tension introduced into the Bowiden-wire 29 by such a spring, I provide a friction -brake for the control pulley 22. Conveniently, this brake is located between the lower face of "the control pulley and the upper face of the partition l1, and may constitute a member 90 of some resilient sheet-metal which .is deformed to bear viyiel'dingly against the partition I! and the bottom'of the pulley '22.

To maintain the bottom of the cup 45 out of contact with the heads of the screws) or with the upper surface of the flange 35, the bushing 21,, with which the cup 45 is rigid, may be pro- Vided withan exterior shoulder 9| Whichengages the upper face of the pulley 22. The bushing 2|, and the 'cup45 which it bears, may be prevented .from either axial or angular displacement by means of :a set screw 92 in the arm Ii].

It will be noted that the cup 45 and the parts which it supports, such as the control unit 56 and the escutcheon plate 6!, are all supported from 'the bushing 2:! "which is normally held'stationary by the set :screW-S2. Thus, rotation of the knob 35 is efiected without displacement of the cup 45 or the escutcheon plate 6|. This construction enables .me to use a relatively large diameter kIIQb 35 whoseangularzpositio-n can be nicely adjusted bythe hand of the operator and I thus eliminate the necessity for any gearing or other speed-reducing mechanism.

In installing the control unit in an automobile, the arm 1-6 is first clamped to the steering post II in :any position which "the user may desire. The radio set may be turned on-and tuned to some broadcasting station, preferably a station broadcasting on a frequency near one end or near the middle of the broadcast band. The set may then be turned off.

The set screw 92 is now loosened, and the cup 45 and bushing 2| withdrawn from within the knob 35, thus exposing the heads of the screws Mmvhich are then loosened to render the knob "35 rotatable relatively to the pulley 22. While the policy :22 is maintained stationary in the .position to which it was brought during tuning operation, the knob '35, in which the dial 135 has been replaced, is then rotated relatively to the pulley22 :until that graduation of the'dial 65 corresponding to the frequency'to which the radio set is tuned is in the position desired by the user :for the :positionof the index, usually at the top of the dial as the 'user views it. Following'this the screws 40 are tightened to clamp the knob to the pulley 2-2. The dial =65 is then removed and the device, reassembled. If desired, the user to which the radio set :has been tuned. hfter the adjustment is affected, the screw 92 may be tightened.

As is custoniary, the:slot :59 of the .fitti-ng is so disposed that the key 54 can be withdrawn only'when the control unit 50 has been adjusted to shut the radio set-off. When it is desired to operate'the set, the key 54 is inserted, the shank passing through the slet 50 in the fitting and into the slotted upper end of the shaft 53. The key may then be turned to rotate the shaft thus turning the set on and initiating the supply of current to the lamp l2. Tuning is then eifected'by rotating the knob 35, the graduations of the'dial 65 which successively appear in alinement with-the index slot 56 indicating the tuning of the receiving "set.

In themodification of my invention illustrated in Figs8 and 9, the adjustable electrical devices such .asthe volume-control unit 50 and the toneoontrol unit 82 are not supported from the arm H3, but instead are mounted in association with other electrical apparatus of the set and are mechanically "connected to rotatable operating members carried bythe'arm 'fll. Themechan'ism for moving the Bowden-wire 29 to eifect tuning adjustments of the radio set is substantially the same in Fig. 7 as it is in the construction illustrated in Figs. 1 we inclusive. Instead of using the short bushing 2|, however, I employa much longer bushing 109 which extends completely through the'arm 10, passing through the opening 23 in the partition I! and also through an alinedopening in the bottom wall of the arm m. Above the pulley 22, the bushing lllfi is provided with a'n annular-flange NH which serves the same purpose as the head 9! of the bushing 2|.

In an upward direction, the bushing I00 extends axially beyond the upper end of the-control knob fifi and supports the-escutcheon plate 6'] and a la'mp-bulb socket H12 in which may be mounted the lamp bulb used to illuminate the dial 65.

For the purpose of securing the-escutcheon plate El to the bushing I00 it is provided with an elongated hub [03 adapted to be clamped between an annular flange I04 on the bushing IUD and-a nut H35 screw-threadedly mounted on the :upper end of the bushing.

Within the upper end of the bushing I mount a rotatable sleeve I'GB, the exterior surface of which intermediate its ends is reduced in diameter to leave at the lower end of the sleeve an annular flange Hi? and at the upper end of the sleeve a. head I08, both of which receive bearing support from the bushing I09. Withdrawal of the sleeve 185 from the bushing I0!) is normally .prevente'd by means of a screw H [I which ext-ends throughthe wall of the bushing above the flange I07 and which may be availed of to mount a. bracket l'l! carrying the socket I02. To the upper end of the sleeve 'IDBis affixed a control knob 113, the connection between the control knob and the sleeve conveniently being effected by knurling the exterior surface of the sleeve and pressing it into the central opening in the knob.

The lower surface of the knob "i l3 may have an axial recess for the reception of the nut I85 to improve the'appearance of the device.

Centrally mounted in the sleeve [05 is a ro- Eta'table stem H4 held in place by a bushing H5 -which is screw-threadedly received in the upper,

end of the sleeve I06. The upper end of the bushing I I4 is counterbored'and closed by a plate H9 having a central slot for the passage of the tang of a key I. The lower end of the key extends into an axial slot 4' in the stem II4, so that the'stem can be rotated by rotating the key. Preferably, the slot I I4 has a width greater than the thickness of the key-tang, and in the spaces between the sides of the key-tang and the walls of the slot there are located the two legs of a U-shaped spring clip I I8 which resiliently presses against the walls of the opening and also against the keyto preventrattling. The plate I I is rotatable with the key I I1 relatively to the bushing II5.

In the preferred arrangement, the stem H4 is utilized to control volume, while the sleeve I06 is utilized to efiect tone-control. As previously indicated, an electrical unit used to provide tone control is directly associated with other electrical apparatus of the set, and is indicated at 82 in Fig, 8. The volumecontrol unit 50 is also associated with other electrical apparatus and may be mounted closely adjacent the tone-control unit 82. The two control units 50 and 82 are connected respectively to the stem H4 and members I24 and I25 located in suitable bearing secured to the lower end of the bushing by means openings inthe lower end of the bushing I00. Mating connecting members I25 and I21, which also receive bearing support from the lower end of the bushing I00, are connected respectively by flexible shafts I28 and I29 with the stem H4 and sleeve I06. The sheaths I 22 and [:23 are of set screws I30.

The flexible shafts I20, I2I, I28, and I29 are conveniently a common form of flexible shaft comprised of two or more layers of oppositely wound helical wires. The upper end of the shaft I28 is aflixed, as by soldering, in an-axial opening in the lower end of the stem II 4 The shaft I29 may pass through an opening in the flange I01 of the sleeve I08, and may be fastened therein as by soldering. Preferably, the shaft I29 extends upwardly beyond the flange I01 so that, in cooperation with the screw I I 0, it serves to prevent a complete rotation of the sleeve.

While the shafts I20 and I2I might, as indicated above, extend upwardly for directconnection to the stem II 0 and sleeve I05, I prefer to employ the intermediate shafts I28and I29 illustrated in Fig. '7 because they facilitate removal of the bushing I00 from the arm I0 and also because they enable the shafts I20 and I2I and the sheaths I22 and I23 to be supplied in such lengths as are required by any given installation. r

Current for the lamp'bulb mounted in the socket III may be supplied through a wire I3I which extends from the socket III through an opening I 32 in the wall of the bushing I 00 and then axially through the lower end of. such bush- The Bowden-wire 29 and its casing 30 extend 'to a point adjacent a pulley I35 mounted on the end of the shaft I36 which carries the adjustable elements of the tuning condensers.- The end of the casing 30 is stationarily supported,

.of the escutcheon plate to prevent as by' means of 'a clamp I31, while the Bowdenwire projects beyond the end of the casing30 and is received in a circumferentially extending groove in the pulley I35. Atorsion spring I38, acting between the pulley I35 and some convenient stationary part, tends to rotate the pulley I35 and shaft I30 in opposition to tension in the Bowden-wirei 29;

The form of brake shown in Fig. 7 for opposing movement of the Bowden-wire 29 androtation of the knob 35 under the influence of the torsion spring I38 is slightly different from that shown in Fig. 4. In Fig. 7, the partition I] is shown as being provided with an annular series of upwardly opening pockets in each of which is located a coil compression spring I40. The upper ends of the springs I40 bearagainst a fibre wash- 7 er MI and force it into frictional engagement 'with the lower surface of the pulley'22.

The control unit illustrated in Figs. 7to 9 can be set up and adjusted in the same way as that shown in Figs. 1 to 6. I may, however, eliminate the necessity for any relative angular adjustment between the knob 35 and pulley 22 by pro viding for relative angular adjustment of the dial 65 and the knob 35. In the construction illustrated in Figs. 4 and 6, the dial had only one position of adjustment relative to the knob 35; but, by providing the dial 65 with an annular series of notches I5 and theknob 35 with an annular series of correspondingly spaced bosses "I6 adapted to receive such notches, provision is made for placing the dial in any of a number of different angular positions relative to the knob 35. As shown in Fig. 9, there are. four of the notches I5, so that four positions of angular adjustment of the dial relative to the knob are possible; Conveniently, the dial 65 is provided around its edge with a downwardly extending annular flange 65' in which the notches I5 are formed.

In the construction illustrated in Figs. 7 and 9 the index which co-operates with theseries'of graduations on the dial 55 is shown as a pointed projection I II in one wall'o-f the dial-exposing opening 56 in the escutcheon plate. This eliminates the necessity for the plate 68 of translucent material which is shown in Fig. 6 and which bears an index in the form-of a light-transmitting radial slot 61.

A washer I of felt or some similar material 50 may be located between the escutcheon plate'BI and the dial 65 and surrounding'the hub I 03 entrance of dust into the interior of the knob. I I claim as my invention: 7 r 1. In a remote control unit for a radio set, a

base, a member rotatably supported from said base, said member having aradially outwardly directed annular flange near its lower end, a

washer secured to said base and overlying said flange to prevent separation of the member and base, and a flexible element having one end sea cured to said member and partiallyencircling said member above said flange and in the plane of said washer, said washer having in its lower face a tangential groove'through which said flexible element passes. v V

2. A remote control unit for an automobile radio .set, comprising an arm adapted to be secured to the steering post of an automobile and to extend laterally therefrom, a'drum rotatably mounted in said arm near the outer end thereof onaniaxis transverse to the arm and generally parallel to the steering post, a'Bowden Wire secured to said drum to be wrapped tlierearound as the drum is rotated, said Bowden wire extending from said drum and having its remote end adapted for connection to a movable element of the radio set, a member secured to said drum and rotatable therewith said member being provided with a circumferentially extending series of graduations and being angularly adjustable relative tosaid drum about the drum-axis, and an index carried by said arm and co -operating with said graduations.

3. A remote control unit for a radio set, comprising a base, a control knob rotatably mounted on said base and adapted Ior mechanical connection with movable parts of the radio set, said knob being cup-shaped and having its open end remote from said base, a stationary support secured to said base and projecting outwardly therefrom into said knob, a circular plate rigidly secured to said support and closing the open end of said knob, said plate being provided with an opening, and said knob being provided interiorly with a circumferentially extending scale visible through the said opening in said plate.

4. In a control unit for a radio set, two relatively rotatable co -axial control members, a rotatable shaft secured centrally to one of said control members, and a second rotatable shaft secured to the other of said control members, said second shaft being flexible and being secured to its associated control member at an eccentric point thereon.

5. A remote control unit for a radio set, comprising a base, a cup-shaped control knob rotatably mounted on said base and adapted for mechanical connection with an adjustable tuning unit in the radio set, the open end of said knob being remote from said base, a stationary support secured to said base and projecting outwardly therefrom into said knob toward the open end of said knob and through the opposite end thereof, and a control member for electrical apparatus, said control member being movably mounted in said support and being accessible for operation through the open end of said knob.

6. A control unit as set forth in claim 5 with the addition of a stationary plate closing the open end of said knob, said plate having an opening, the control member of said electrical apparatus being rotatable about an axis in alinement with said opening.

EARL C. BOOTH. 

